Electric horn



Nov. 12, 1929. R. M. CRITCHFIELD I ELECTRIC HORN Filed June 13. 1925 1c ratchet with respect to the anvil.

Patented Nov. 12, 1929 UNITED STATES ROBERT M. CRITCHFIELD, F ANDERSON,

ATENT OFFICE INDIANA, ASSIGN'OR, BY MESNE ASSIGN- MENTS, TO DELCO-REMY CORPORATION, OF DAYTON, OHIO, A CORPORATION 01 DELAWARE nLnc'rn-Io Home Application filed June 13, 1925. Serial No. 36,951. V

This invention relates to sound producing apparatus such as signalling horns for automobiles, and particularly the type of horn which includes a vibratory diaphragm, a

sound projector and an electric motor which operates a ratchet intermittently engaging an anvil connected with the diaphragm.

One of the objects of the invention is to provide improved means for adjusting the In the form of invention disclosed, this is accomplished by mounting the ratchet upon the armature shaft of the motor and adjusting the shaft endwise by a novel arrangement of parts which is conducive to economy in manufacture.

Further objects and advantages of the pres ent invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings: Fig. 1 is a fragmentary longitudinal sectional View of a motor-driven horn including the present invention;

Fig. 2 is, an end view of the horn motor frame, looking in the direction of the arrow 2 in Fig. 1;

Fig. 3 is a side view partly in section, of a screw used for adjusting the motor shaft;

screw shown in Figs. 3 and 4; and

Figs. 6 and 7 are sectional views taken respectively on the line 6-6 and the line 77 of Fig. 5.

Figs. 3 to 7 inclusive, are drawn to a larger scale than Figs. 1 and 2.

Referring to the drawings, the horn includes two frustro-conical frame members 20 and 21, having flanges 22 and 23, respectively. Spacing washers 24 and 25, and a diaphragm.

26 are included between the flanges 22 and 23 and are secured in position by suitable screws (not shown), which pass through the flanges. The member 21 supports a sound projector 27. j y

The frame member 20 supports a U-shaped motor field frame 30, to which is attached a core member 31 carrying :a pole shoe 32. The core .31is surrounded by a field magnet winding 33. The lower branch of the U-shaped frame 30 is formed cylindrically to provide a field pole 34. A shaft 35 is supported by bearings 36 and 37, supported respectively by the field frame 30 and the member 20. The shaft 35carriesa commutator 38 and an armatu-recore 39 having windings, and rotatable between the pole sh0e32 and the pole 34. Shaft 35 is provided with a squared end 40 for entering a rectangular opening in a ratchet 41 which cooperates with'an anvil 42 attached to the-diaphragm 26. The ratchet 41 is retained on the shaft 35 by a screw 43.

. In order to adjust the position of the ratchet 41 with respect to the anvil 42, the shaft 35 is adjustable endwise in its bearings 36 and 37. i

This adjustment is accomplished by the turn ing of a'screw 44, threadedly engaging the frame 30 and contacting with the free end of a spring 45 secured by a rivet'46 to the frame 30. The spring 45 shown in the form of aleaf spring engages the rounded end 47 of the shaft 35.

I The armature core is decentered with respect to the pole shoe 32 and pole 34 in order to maintain the shaft end 47 in engagement with the spring 45. The inner end face of the head of screw 44 is provided with radial notches 52, each adapted to be engaged by a ridge 53 provided by the spring 45. The screw 44 is, therefore, yieldingly maintained in adjusted position by the cooperation between the ridge 53 and one of the notches 52. The screw 44 passes through a slot 54 in the spring 45 and also through a washer 55 which surrounds the shaft 35. The washer 55 is made of felt or other oil-absorbing, fibrous material, and supplies lubricant to the bearing 36 and to the engaging surfaces of the shaft end 47 and spring 45. A similar washer 56, attached to frame 20, supplies lubricant to the bearing 37. The motor frame is surrounded by a housing which is supported by the frame 20 and is provided with a hole '61 for receiving the head of the screw 44, so that adjustment of the horn may be made without removing the housing 60.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In a device of the character described, the combination with an endwise movable shaft, means for adjusting the shaft endwise, said means including a leaf spring engaging the end of the shaft, one end of said leaf spring being fixed, the other being provided with an adjusting screw to move the spring toward or away from the shaft.

2. The device defined by claim 1, in which, however, the spring and screw are provided with cooperating ridges and recesses to maintain the screw in proper spring adjusting position.

3. In a device of the character described, the combination with a support provided with a bearing, a rotatable member journaled in said bearinv and movable axially relative thereto; anc means for limiting said axial movement of the said member relative to the bearing, said means including a lever having its intermediate portion engaging one end of the rotatable member, one end of the said lever being hinged to the bearing support and the other end of the lever being adjustably secured thereto.

4:. In a device of the character described, the combination with a support provided with a bearing, a rotatable member journalled In said bearing and movable axially relative thereto; and means for limiting axial movement of the member in one direction, said means comprising a leaf spring lever attached at one end to the support and having a portion engaging the rotatable member, and a screw cooperating with the leaf spring and support to vary the relation between the support and the part of the spring which engages the rotatable member.

5. In a device of the character described, the combination with a support provided with a bearing, a rotatable member journalled in said bearing and-movable axially relative thereto; and means for limiting axial movement of the memberin one direction, said means comprising a leaf spring lever attached at one end to the support and having its intermediate portion engaging the rotatable member, and a screw passingthrough the free end of the spring and threadedly' engaging the support.

In testimony whereof I hereto aflix my signature.

ROBERT M. CRITCHFIELD. 

